"The Castglo King is a 1950s gem! Patented by John H. Dean of Rochester, NY, in April 1951, the paperwork promises "Many hours of enjoyable fishing." Dean's true objective was to enable the angler to fish in water deeper than the length of the pole - beyond which casting becomes difficult. Because the Castglo worked primarily as a slip bobber it would sit almost on the sinker when cast. On hitting the water, the sinker would pull the line thru the bobber until striking bottom, causing the line to slacken and the bobber to fall flat. When a fish tugged at the baited hook the Castglo would swing upright, alerting the angler to strike. Once the hook was set and the line tightened, the bobber would again slip down the line making retrieval easy. You could see a Castglo coming - it was luminous white one side and colored red on the other. They are worth around $15 but with the packaging intact that could easily double. I've seen different paperwork which suggests the Castglo was made in Toronto - where it was referred to as the Castglo King - and in Rochester, NY where makers Big Eight Enterprises Inc. simply called it the Castglo Bobber. A great find!